1. Field of the Invention
The present invention relates to an electron beam apparatus which uses electron-emitting devices and which is applied to a flat panel type image display apparatus (flat panel display) and, more particularly, to an electron beam apparatus having a feature in an electrode construction of a rear plate.
2. Description of the Related Art
Hitherto, an image forming apparatus can be mentioned as a using form of electron-emitting devices. For example, there is a flat panel type electron beam display panel in which an electron source substrate (rear plate) formed with a number of cold cathode electron-emitting devices and an opposite substrate (face plate) having anode electrodes each for accelerating an electron emitted from the electron-emitting device and a light-emitting member are arranged in parallel so as to face each other and the inside of the display panel has been evacuated in vacuum. According to the flat panel type electron beam display panel, a lighter weight and a larger screen can be realized as compared with those of a cathode ray tube (CRT) display apparatus which is widely used at present. An image of higher luminance and higher quality can be also provided as compared with those of a flat panel type display panel using a liquid crystal or another flat panel type display panel such as plasma display, electroluminescence display, or the like.
In the image forming apparatus of the type in which a voltage is applied between the anode electrode and the device in order to accelerate the electron emitted from the cold cathode electron-emitting device as mentioned above, it is advantageous to apply a high voltage in order to obtain the maximum light-emitting luminance. Since the emitted electron beam is diverged depending on a device type until it reaches a counter electrode, in order to realize the display with high resolution, it is desirable that an interplate distance between the rear plate and the face plate is short.
However, if the interplate distance is short, since an electric field between the plates inevitably becomes high, such a phenomenon that the electron-emitting device is broken by a discharge is liable to occur.
In Patent Document 1 (Japanese Patent Application Laid-Open No. H05-299010), there has been disclosed such a construction that in an electron source of a field emission type, by providing a fusing portion between a field emission electrode and an electric supply line, an influence on a peripheral portion that is caused due to a short-circuit which has occurred locally is suppressed. In Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-343230), there has been disclosed such a construction that in an electron source of a field emission type, by providing a narrow portion between a surface electrode and a bus electrode, the narrow portion is disconnected when an overcurrent is generated, thereby suppressing an influence on a peripheral portion.